Deep Space Maneuvers
Deep space maneuvers are engine burns done at far distances from any celestial body. Their purpose is to adjust the trajectory of a ship, so that it will enter the Sphere of Influence of a targeted body. Examples NASA's Osiris Rex mission performed deep space maneuvers on its way to asteroid Bennu. In the same way, NASA's Juno ship performed deep space maneuvers to get in position for an Earth gravity assist, to reach the orbit of Jupiter. JAXA's mission to Venus performed a set of DSMs after failing to enter the orbit, to get in the correct place for a later orbit insertion. Principles Deep space maneuvers are done usually at the furthest point of the orbit (usually aphelion or perihelion), to slightly correct the trajectory, to enter the sphere of influence of a celestial body. Deep space maneuvers don't benefit from the Oberth effect, so the fuel consumption is greater. So, it's important to use them for minor course correction only. How To Such maneuvers are largely used for Venus flybys, in a Mercury Return Mission. However, they can be used for Moon, Mercury and Earth flybys. An advantage of Spaceflight Simulator is that you can accelerate time and endure long missions without repercussions. #Set target to the celestial body you want to use for Gravity Assists. Your orbit path must intersect that body. #Accelerate time until the ship gets very close to cross the sphere of influence. This might take patience. #When the ship will get very close to the target, wait until the ship is positioned at the highest distance on its orbit. #When the ship is at the highest distance on its orbit, zoom in and examine the closest approach point (the dashed line). See if the ship will get there before or after the target. The dashed line shows where the target will be when the ship will hit the crossing point between orbits. Basic Principles Here are the basic engine burns: #If the ship arrives at orbit crossing point before the target and the target is closer to the Sun, fire the engines forward. #If the ship arrives at orbit crossing point after the target and the target is closer to the Sun, fire the engines backward. #If the ship arrives at orbit crossing point before the target and the target is further to the Sun, fire the engines backward. Point after the target and the target is further to the Sun, fire the engines forward. Additional Principles Sometimes, it might not be possible to get to target like this. When you do the engine burns, zoom in and see if the distance to the target is really decreasing. This is important especially when the target is not at the aphelion or perihelion (closest or furthest point to the Sun) of your ship's orbit. Sometimes, it simply might not be possible to get too close. Some players try to perform different engine burns: towards the Sun and away from the Sun. These maneuvers have some efficiency, but not like burning the engines forward or backwards. High cost Maneuvers These kind of maneuvers are done when a ship burns a lot of fuel and strongly changes trajectory while in a heliocentric orbit. They are performed when: #A ship tries to reach the Sun. #A ship failed to reach its target. #The astronaut finds out it has not enough fuel and tries to return home. #Others (for example, a suicide mission). See Also *Advanced Orbital Mechanics *Aerobrake *Gravity Assists *Oberth Effect *Trajectory Correction Maneuvers Category:Gameplay Category:Tutorial